Cardinal Marc Ouellet of Canada has earned the respect of his colleagues as head of the Vatican's office for bishops, a tough and important job vetting the world's bishops. He is 68.
Cardinal Francis Arinze of Nigeria, 80.
Cardinal Peter Appiah Turkson of Ghana is one of the highest-ranking African cardinals at the Vatican, currently heading the Vatican's office for justice and peace. At 64, he is prone to gaffes and is considered something of a wild card.
Cardinal Angelo Scola, the archbishop of Milan, was among the few Italians who was considered in the running by outsiders. Scola, 71, is close to Benedict, has a fierce intellect and leads the most important archdiocese in Italy -- no small thing given that Italians still dominate the College of Cardinals.
Cardinal Gianfranco Ravasi head of the Vatican's culture office. At 70, he is another intellectual heavyweight who quotes Hegel and Nietzsche as easily, and almost as frequently, as the Gospels.
Cardinal Antonio Tagle, the archbishop of Manila, is a rising star in the church, but at 56 and having only been named a cardinal last year, he is considered too young.
Cardinal Joao Braz de Aviz, 65, of Brazil, has earned praise as head of the Vatican's office for religious congregations, even though he's only held the job since 2011. He has had the difficult task of trying to rebuild trust between the Vatican and religious orders that broke down during his predecessor's reign.
OTHER LEADING CANDIDATES FROM SOUTH AMERICA:
Cardinal Odilo Pedro Scherer, 63, archbishop of Sao Paulo.
Cardinal Leonardo Sandri, 69, of Argentina, head of the office for Eastern rite churches who was the "voice" of Pope John Paul II when the pontiff lost the ability to speak because of Parkinson's disease.